U.S. patent application number 11/464796 was filed with the patent office on 2007-02-08 for refillable tape cassette.
Invention is credited to Robert Day, Geert Heyse, Charles Robert Sims.
Application Number | 20070031171 11/464796 |
Document ID | / |
Family ID | 8227685 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070031171 |
Kind Code |
A1 |
Heyse; Geert ; et
al. |
February 8, 2007 |
REFILLABLE TAPE CASSETTE
Abstract
The invention refers to a refillable tape cassette (2,7) for
accomodating a supply of printable tape. In order to avoid the need
for different tape cassettes for different tape widths it is
proposed that the tape cassette (2,7) is capable of selectively
housing supplies of tapes of different widths. Alternatively or
additionally, the tape cassette (2,7) can have a housing comprising
a base (40) on which said tape supply can be releasably fixed, and
a lid (42) fixed to said base (40), wherein the lid (42) is
pivotally mounted to said base by means of a hinge (46). Further,
proposals are made to hold the windings of refill tape units (30)
together by means of a strip (60) of adhesive or wax on the axial
ends of the units, or by scuffing the backing layer (9) of an image
receiving tape (4) which is broader than the image receiving
layer.
Inventors: |
Heyse; Geert;
(Sint-Katelijne-Waver, BE) ; Day; Robert;
(Cambridge, GB) ; Sims; Charles Robert;
(Hertfordshire, GB) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN LLP
233 S. WACKER DRIVE, SUITE 6300
SEARS TOWER
CHICAGO
IL
60606
US
|
Family ID: |
8227685 |
Appl. No.: |
11/464796 |
Filed: |
August 15, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09182499 |
Oct 30, 1998 |
7097372 |
|
|
11464796 |
Aug 15, 2006 |
|
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|
Current U.S.
Class: |
400/615.2 |
Current CPC
Class: |
B41J 35/28 20130101;
B41J 33/52 20130101; B41J 32/00 20130101 |
Class at
Publication: |
400/615.2 |
International
Class: |
B41J 11/00 20060101
B41J011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 27, 1997 |
EP |
97 120 793.1 |
Claims
1. A tape cassette comprising: a supply of printable tape; and a
removable holder having a supply spool and a take up spool for ink
ribbon, such that the relative position of the supply spool and the
take up spool corresponds to their respective positions when the
holder is in the cassette.
2. A tape cassette as claimed in claim 1, wherein the printable
tape comprises an image receiving layer and a releasable backing
layer.
3. A cassette as claimed in claim 1, wherein said holder is
configured to define a path of said ink ribbon, said path
corresponding to the path of the ink ribbon when said holder is in
the cassette.
4. A cassette as claimed in claim 1, wherein said holder comprises
a lid covering at least a part of said cassette.
5. A cassette as claimed in claim 1, wherein said holder comprises
a plastic moulded frame supporting said supply spool and said take
up spool.
6. A cassette as claimed in claim 1, wherein said holder is
configured to match and/or mate with said cassette.
7. A cassette as claimed in claim 1, wherein said ink ribbon is
wound in position between the supply spool and a cassette exit and
is arranged to enter the cassette again after passing a print
zone.
8. A cassette as claimed in claim 7, wherein a guide is provided
for guiding said ink ribbon to said take up spool.
9. A tape cassette comprising a supply of printable tape and
configured to receive one of a plurality of removable holders, each
holder having a supply spool and a take up spool for ink ribbon,
such that the relative position of the supply spool and the take up
spool corresponds to their respective positions when the holder is
in the cassette, said removable holders comprising differently
coloured ink ribbon.
10. A tape cassette comprising a supply of image receiving tape and
ink ribbon tape is provided on a supply spool, and a leading end of
the ink ribbon being connected to a take-up spool, the supply spool
and the take-up spool being fixed to a holder such that their
relative position corresponds to their position when they are
inserted in said tape cassette.
11. A tape cassette as claimed in claim 10, wherein said holder is
configured to define the path of said ink ribbon tape, such that
the path corresponds to the path of the ink ribbon when it is
inserted into the tape cassette.
12. A tape cassette as claimed in claim 10, wherein the ink ribbon
supply spool and the ink ribbon take-up spool are releasably
secured by said holder against rotation, such that the cassette is
in an operable state when the ink ribbon is mounted in said tape
cassette, but released from the holder.
13. A tape cassette as claimed in claim 12, wherein the ink ribbon
supply spool and the ink ribbon take-up spool are fixed to said
holder by means of a tear-off tape.
14. A tape supply unit comprising a wound tape, the tape unit being
suitable for being detachably loaded in a tape cassette and/or in a
tape printing device, wherein the respective windings of the tape
are held together by means of a strip of wax or adhesive provided
on the axial end or ends of said tape supply unit.
15. A tape supply unit comprising a wound image receiving tape, the
tape unit being suitable for being detachably loaded in a tape
cassette and/or in a tape printing device, wherein the image
receiving tape comprises an image receiving layer of a first width
and a releasable backing layer of a second width, the second width
being larger than the first width, and wherein the axial end or
ends of the tape supply unit are scuffed such that the respective
windings of the tape are held together.
Description
[0001] The present invention relates to a cassette for a tape
printer.
[0002] Known tape printing apparatus of the type with which the
present invention is generally concerned are disclosed in EP-A-0
322 918 and EP-A-0 322 919 (Brother KK) and EP-A-0 267 890
(Varitronic). The printers each include a printing device having a
cassette receiving bay for receiving a cassette or tape holding
case. In EP-A-0 322 918, the tape holding case houses an ink
ribbon, a transparent image receiving tape and a double-sided
adhesive tape which is secured at one of its adhesive coated sides
to the image tape after printing and which has a backing paper
peelable from its other adhesive side. With both these apparatus,
the image transfer medium (ink ribbon) and an image receiving tape
(substrate) are in the same cassette.
[0003] The present applicants have developed a different type of
tape printing apparatus which is described for example in U.S. Pat.
No. 5,456,545. In this printing apparatus, the substrate tape is
similar to that described in EP-A-0 267 890 (ie. comprises an image
receiving layer and a releasable backing layer) but is housed in
its own tape holding case while the image transfer ink ribbon is
similarly housed in its own tape holding case.
[0004] In all of these cases, the image receiving tape passes in
overlap with the ink ribbon to a print zone consisting of a fixed
print head and a platen against which the print head can be pressed
to cause an image to transfer from the ink ribbon to the image
receiving tape. There are many ways doing this, including dry
lettering or dry film impression, but the most usual way at present
is by thermal printing where the print head is heated and the heat
causes ink from the ink ribbon to be transferred to the ink
receiving tape. Alternatively, the print head may be in direct
contact with a thermally sensitive image receiving tape whereby
when the print head is heated, an image is defined on the image
receiving tape.
[0005] A disadvantage of the known tape cassettes is that once the
supply of tape housed in the cassette is printed, the user needs to
buy an entirely new cassette, while the empty cassette is
discarded. In order to avoid wastage of material, it has thus been
proposed to have refillable cassettes, into which the user can
insert new printing tape and/or ink ribbon. Such cassettes are
described eg. in EP-A-0 625 427, EP-A-0 629 509, EP-A-0 630 756,
EP-A-0 633 141, EP-A-0 635 375, EP-A-0 694 415, EP-A-0 704 311,
EP-A-0 734 878, EP-A-0 790 134 and DE-U-295 20 421.
[0006] Such cassettes allow the user to use one tape cassette with
a multiplicity of image receiving tapes and/or image transfer tapes
(ink ribbon). A disadvantage is however that the refillable
cassettes known in the prior art only allow to insert a certain
width of tape. Thus, a user needs a relatively high number of tape
cassettes, since this number equals to the number of different tape
width which are intended to be used.
[0007] The object of the present invention is thus to provide a
refillable tape cassette which avoids the need for different
cassettes for distinct tape widths.
[0008] According to a first aspect of the present invention, there
is provided a tape cassette for accomodating a supply of printable
tape, the tape cassette being suitable for being detachably loaded
in a tape printing device, said tape cassette having means for
inserting and removing a tape supply into said tape cassette, and
wherein the tape cassette is capable of selectively accomodating
tape supplies of different tape widths.
[0009] The idea of the invention is to provide a single tape
cassette which is capable of selectively housing tape supplies of
different width. Thus, the user can fill his refillable tape
cassette through an appropriate opening with the tape supply with
the desired tape width. The tape cassette has hence means for
accomodating tape supplies of different width. The tape can be an
ink ribbon tape and/or an image receiving tape comprising an image
receiving layer and a releasable backing layer.
[0010] In order to selectively accomodate tapes of different width,
it is necessary to define the plane in which the tape is located
within the cassette. It is thus proposed that the tape is wound
onto a bobbin which is releasably accomodated on a post provided
within said cassette, the post comprising a datum surface which
interacts with a surface of said bobbin such that it defines the
position of the bobbin in the axial direction of the post. Further,
the post or the bobbin can comprise a rib mating with an internal
flange of the bobbin or the post, so that the bobbin is releasably
retained on the post.
[0011] It is preferred that bobbins with tape supplies of different
tape widths have surfaces interacting with the datum surface of the
post, wherein the surfaces are positioned so that the centre line
of tapes of different width is located in the same plane,
independent on the width of the tape.
[0012] In order to achieve good printing quality, it is necessary
to provide a back tension in the tape. Thus, a spring may be
provided between a bobbin onto which said tape is wound and a part
of the housing of the tape cassette, the spring slipping on said
housing and/or on said bobbin and providing back tension in said
tape. When the spring interacts with a flange of said bobbin, and
the relative position of the flange with respect to the post and
thus the backward tension of the tape provided by the spring
depends on the width of the tape, it is possible to have an
appropriate tension in the tape, which depends on the tape width.
The spring may be unitary with the bobbin or the housing of the
tape cassette.
[0013] The housing of the tape cassette can have different forms.
It can consist of a base on which said tape supply can be
releasably fixed, the base having a bottom surface extending
parallel to the center plane of the tape supply, the tape supply
being releasably retained on said bottom surface, and wherein the
tape supply is freely accessible from the side opposite said bottom
surface, the cassette thus having the form of an open chassis
without a lid.
[0014] Alternatively, the cassette has a housing comprising a base
on which said tape supply can be releasably fixed, the base having
a bottom surface extending orthogonally to the center plane of the
tape supply, the tape supply being releasably retained on said
bottom surface, and wherein the tape cassette comprises a lid
opposite said bottom surface, wherein the distance between said
bottom surface and said lid varies with the width of said tape. In
this case, a pin can connect base and lid and provide a guidance
for the lid on the base. The lid can be held in position by means
of a clip which can be accomodated on corresponding surfaces of the
base or the lid, and secures the lid to the base, whereby the
respective surface in with which the clip interacts depends on the
width of the tape. It is further possible to have a plurality of
such clips, whereby it depends on the tape width which one of the
clips is interacting with the lid.
[0015] When a thermal transfer printing process is performed in the
tape printing device, it is necessary to provide an ink ribbon.
This ink ribbon can be located in its own cassette (see U.S. Pat.
No. 5,456,545), or in the same cassette as the image receiving
tape. In both cases the ink ribbon tape is wound on a supply spool,
and its leading end is connected to a take-up spool. Since the ink
ribbon must follow a predetermined path such that printing can take
place with high quality, it is necessary to insert it appropriately
into the cassette. This can be done manually by the user, or the
supply spool and the take-up spools can be fixed to a holder such
that their relative position corresponds to their position when
they are inserted in said tape cassette. The holder thus
facilitates insertion of the ink ribbon into the cassette. It can
additionally define the path of said ink ribbon tape, such that the
path corresponds to the path of the ink ribbon when it is inserted
into the tape cassette. In order to prevent unintended rotation of
said spools, it is proposed that they are releasably secured by
said holder against rotation (and hence unwinding), such that the
cassette is in an operable state when the ink ribbon is mounted in
said tape cassette, but released from the holder. In a preferred
embodiment, the ink ribbon supply spool and the ink ribbon take-up
spool are fixed to the holder by means of a tear-off tape. Further,
the holder may comprise a lid covering at least a part of said tape
cassette.
[0016] In another embodiment of the invention, the tape cassette
has a housing comprising a base on which said tape supply can be
releasably fixed, the base having a bottom surface extending
orthogonally to the center plane of the tape supply, wherein the
tape cassette comprises a lid opposite said bottom surface, whereby
the tape supply is releasably fixed to the lid. The user can thus
grip the lid with the tape, and simply insert it into the base of
the tape cassette. The lid can comprise material (paper, cardboard
or plastics) between the tape supply and the outer surface of the
lid such that the distance between the bottom of the tape cassette
and the outer surface of the lid is independent on the width of
said tape.
[0017] According to a second aspect of the invention, there is
provided a tape cassette for accomodating a supply of printable
tape, the tape cassette being suitable for being detachably loaded
in a tape printing device, wherein the tape cassette has a housing
comprising a base on which said tape supply can be releasably
fixed, and a lid fixed to said base, wherein the lid is pivotally
mounted to said base by means of a hinge.
[0018] The tape cassette thus only consists of a single part, since
the lid and the base are fixed together. This makes handling
relatively easy. For the sake of reduction of production costs, the
base, the lid, and the hinge can be unitary, ie. moulded in as
single part.
[0019] According to a third aspect of the invention, there is
provided a tape supply unit comprising a wound tape, the tape unit
being suitable for being detachably loaded in a tape cassette
and/or in a tape printing device, wherein the respective windings
of the tape are held together by means of a strip of wax or
adhesive provided on the axial end or ends of said tape supply
unit.
[0020] According to a fourth aspect of the invention, there is
provided a tape supply unit comprising a wound image receiving
tape, the tape unit being suitable for being detachably loaded in a
tape cassette and/or in a tape printing device, wherein the image
receiving tape comprises an image receiving layer of a first width
and a releasable backing layer of a second width, the second width
being larger than the first width, and wherein the axial end or
ends of the tape supply unit are scuffed such that the respective
windings of the tape are held together.
[0021] The third and fourth aspect is thus directed towards the
tape supply units as such. In order to prevent unwinding, what is
in the state of the art usually performed by foils adhered to the
axial ends of the units, or by a strip of adhesive tape connecting
the leading end of the tape to the spools, it is proposed to have a
strip of wax or adhesive on the axial ends of said tape supply, or
to scuff the backing of the image receiving tape, whereby the
backing is wider than the image receiving layer.
[0022] For a better understanding of the present invention and as
to show how the same may be carried into effect, reference will now
be made to the accompagnying drawings in which:
[0023] FIG. 1 is a plan view showing two cassettes inserted into a
printing device;
[0024] FIG. 2 is a perspective view of a cassette insertable into
the printing device of FIG. 1;
[0025] FIG. 3a is a side view of a tape supply spool;
[0026] FIG. 3b is a top view of a tape supply spool;
[0027] FIG. 4 is a view of a tape supply together with its
support;
[0028] FIG. 5 is a view of a broad tape supply together with its
support;
[0029] FIG. 6 is a view of a narrow tape supply together with its
support;
[0030] FIG. 7 is a plan view showing a cassette according to
another embodiment of the invention inserted into a printing
device;
[0031] FIG. 8 is a perspective view of a cassette of FIG. 7;
[0032] FIG. 9a is a bottom view of a tape spool of the cassette of
FIG. 8;
[0033] FIG. 9b is a perspective view of a tape spool of the
cassette of FIG. 8;
[0034] FIG. 10 is a perspective view of another cassette insertable
into the printing device of FIG. 7;
[0035] FIG. 11a-c are sections through a bearing of the tape supply
of the cassette of FIG. 10;
[0036] FIGS. 12a and b are sections through bearings of the tape
supply of the cassette of FIG. 10;
[0037] FIGS. 13a and b are views of the tape spool for use in a
cassette of FIG. 10; and
[0038] FIG. 14a-d are sections of tape supplies for use in a
cassette of FIG. 10.
[0039] FIG. 1 shows in plan view two cassettes arranged in a
printing device 1. The upper cassette 2 is located in a first
cassette receiving portion 26 and contains a supply of image
receiving tape 4 which passes through a print zone 3 of the printer
to an outlet 5 of the printer. At the outlet, a cutting mechanism
is provided for cutting off printed portions of image receiving
tape 4 in order to use them as a label. The image receiving tape 4
comprises an upper layer for receiving a printed image on one if
its surfaces and having its other surface coated with an adhesive
layer to which is secured a releaseable backing layer. The cassette
2 has a recess 6 for accomodating a platen 8 of the printer, and
guide portions 22,24 for guiding the tape 4 through the print zone.
The platen 8 is mounted for rotation within a cage moulding 10. As
an alternative, the platen 8 could be mounted for rotation on a
pin. The lower cassette 7 is located in a second cassette receiving
portion 28 and contains a thermal transfer ribbon 12 which extends
from a supply spool 30 to a take-up spool 32 within the cassette 7.
The thermal transfer ribbon 12 extends through the print zone 3 in
overlap with the image receiving tape 4. The cassette 7 has a
recess 14 for receiving a print head 16 of the printer and guide
portions 34,36 for guiding the ink ribbon 12 through the print zone
3. The print head 16 is movable between an operative position,
shown in FIG. 1, in which it is in contact with the platen 8 and
holds the thermal transfer ribbon 12 and the image receiving tape
in overlap between the print head and the platen and an inoperative
position in which it is moved away from the platen to release the
thermal transfer ribbon and image receiving tape in the operative
position, the platen is rotated to cause image receiving tape to be
driven past the print head and the print head is controlled to
print an image onto the image receiving tape by thermal transfer of
ink from the ribbon 12. The print head is a conventional thermal
print head having an array of pixels each of which can be thermally
activated in accordance with the desired image to be printed. The
printing device has a lid which is not shown but which is hinged
along the rear of the cassette receiving portion and which covers
both cassettes when in place. A motor drives the platen 8 so that
the image is printed print head column wise onto the image
receiving tape 4. The platen 8 drives the image receiving tape
through the print zone 3 under the action of its own rotation. The
rotation of the platen and the energisation of the print head 16
are controlled by a microprocessor.
[0040] In FIG. 2, a perspective view onto an ink ribbon cassette
for use in a printing device as shown in FIG. 1 is given. The
cassette 7 is refillable and has three key elements: a base 40, a
lid 42, and a tape module 41. The lid 42 and base 40 are connected
via a hinge 46. The tape module 41 comprises a plastic moulded
frame 35, which supports the ink ribbon tape supply spool 30, the
tape take-up spool 32, and the guidances 34,36. Thus, the user can
refill the cassette by opening the lid 42, removing and discarding
the spent or empty tape module 41, and inserting a new tape module
41. The shown embodiment is designed for cassettes which house a
single tape, such as the ink ribbon used in the printer of FIG. 1,
and could alternatively or additionally accomodate the tape 4.
Thus, a tape cassette could be produced with an arrangement
corresponding to the cassette 2 shown in FIG. 2, hence containing
only image receiving tape 4, or the cassette could accomodate ink
ribbon and image receiving tape within the same housing, as the
cassette shown in FIG. 7.
[0041] The base 40 and lid 42 are connected by the hinge 46 running
along one edge of the base. In the illustrated embodiment, the
hinge is a so-called "living" type. The lid 42 and base 40 are
formed as a single moulding with a bridge of material joining them
along the hinged edge. The bridge has a relatively small wall
thickness that will deform plastically if the lid portion is
rotated in the direction shown by arrow "X", relative to the base
portion 40. By selecting a plastic with a relatively high modulus
of elasticity a hinge can be made which will flex from the open to
the closed position many times without breaking. Although a living
hinge is the lowest cost and easiest to manufacture solution, many
other types of hinges using separate lid, base and hinge components
could also be used.
[0042] The lid 42 is located accurately to the base 40, as it is
closed, by tapered alignment pins 54 which locate in alignment
holes 56 of the base. The lid 42 is retained by a clip or clips
such as the clip 48 in the illustration, locating in an opening or
openings such as the opening in the base 40 denoted by reference
numeral 58. When the cassette can accomodate different tape widths,
it is possible to have a multiplicity of clips, whereby to each
possible tape width one clip 48 is assigned, such that the
respective clip fixes the lid 42 to the base 40. The base 40
further comprises recesses 52 for locating the tape module 41 as
described below.
[0043] Turning now to the tape module 41, it comprises a plastic
moulded frame 35, which is provided with support posts for the two
tape spools 30,32, whereby the tape spools are assembled to the
posts, and tape is wound onto one of the spools 30, with the
leading end fixed to the second spool 32, when the ink ribbon tape
is new, has thus not yet been used. When the tape is being used for
printing, tape is unwound from the supply spool 30 and wound up on
the take-up spool 32. The tape module 41 has protrusions 50 which
match and/or mate with the recesses 52 in the base 40 of the
cassette. The ink ribbon tape 12 is wound in position between the
supply spool 30 and the cassette exit (which is located at the
guide 34), and--after having passed the print zone 3--enters the
cassette 7 again at the entrance located at the guide 36, from
where it is guided towards the take-up spool 32. Tape tensioning
and retention devices as described below are provided in order to
keep the ink ribbon tape in position.
[0044] As a result, the tape module 41 can relatively simply be
dropped into place in the cassette base 40 without effort or the
need for complex instructions. After insertion, the lid 42 is
closed over the tape module 41, and the clip 48 is latched into the
corresponding hole 58. The tape module 41 is thereafter retained in
the cassette 7 during use.
[0045] The tape 4 and/or the ink ribbon 12 are provided in "naked"
units, ie. without any additional housing, in order to avoid waste
of material. A potential problem is thus that the tape could
unintentionally unwind from the supply spool. Consequently, a strip
of adhesive or a strip of wax is deposited radially on the top
and/or bottom of the ink ribbon tape supply reel 30. This increases
the force required to unravel the spool, thus preventing it from
unwinding in storage (as a result of its own elasticity), but
allows unwinding when driven in the printing device. Reference is
made to FIGS. 3a and 3b, whereby FIG. 3a shows a view from the
side, and FIG. 3b a view from the top. The strip is denoted by the
reference numeral 60. Such a strip of adhesive or wax can be
applied to either tape (ink ribbon 12 and image receiving tape 4),
but is in reality most useful for the image receiving tape which is
relatively stiff and has a strong tendency to uncoil if not
prevented from doing so.
[0046] For correct operation of the printer, and in particular the
avoidance of tape tracking problems, the tape must be kept under
moderate tension when in use. This is achieved by resisting the
rotation of the spool 30 as it unwinds. In FIG. 4 an arrangement
for providing the necessary tension is shown. The plastic moulded
frame 35 of the tape module 41 is provided with a stationary magnet
62 which is located at the center of the support post 37 for the
ink ribbon supply spool 30. The support post 37 has a generally
conical shape, wherein the largest diameter is facing the bottom of
the frame 35. The ink ribbon tape supply spool 30 on the other hand
is conical, as well, with the larger diameter facing towards the
frame 35, and is provided with at least two spool magnets 64, which
interact with the stationary magnet 62 and create an attraction
between the spool 30 and the support post 37 of the frame 35. Thus,
friction is created when the spool 30 rotates. The magnets 62 and
64 attract each other forcing the spool 30 down onto the frame 35.
Consequently, the magnets 62, 64 fulfill two purposes; they keep
the spool 30 in position, and provide the necessary tension for
printing. The magnets are attached to, or moulded into, the two
components, ie. the support post and the bobbin of the spool. The
generated friction opposes the motion of the spool when the tape (4
or the ink ribbon 12) is pulled off it, and in so doing generates a
tension in the tape. The back tension is important in preventing
tape tracking problems with certain types of tape. it is also
desirable when loading new tape modules into the cassette base, as
the tape remains taught is less likely to snag on cassette base
features during insertion.
[0047] Similar solutions are shown in FIGS. 5 and 6. Here, the
support post 37 for the ink ribbon tape supply spool 30 is however
of a cylindrical shape (ie. not conically). As can be seen from
FIGS. 5 and 6, the support post 37 can accomodate ink ribbon tape
supply spools 30 with tape of different width. In FIG. 5, the width
of the tape on the supply spool 30 is much broader than in FIG. 6.
In order to maintain the same level of the center line of the tape
independent on the width, the magnet 62 within the support post 37
is at the same level as the magnets 64 integrated into the supply
spool 30. The level of the magnets 62,64 above the bottom of the
frame 35 corresponds to the centerline of the ink ribbon tape.
Thus, the magnets are used to position the spool 30 axially at the
center of the support post 37. This is of benefit because a single
cassette 2 or 7 or tape unit 41 could be refilled with tapes of
different widths. The magnetic attraction between stationary
magnets 62 and spool magnets 64 is sufficient to overcome the
gravitational force acting on the spool, and prevent it from
dropping to the bottom of the support post 37.
[0048] It should be noted that an arrangement corresponding to
FIGS. 4 to 6 could be provided in a cassette 2 which only houses
the image receiving tape 4, and for an image receiving tape 4 shown
in the cassette of FIG. 7.
[0049] FIG. 7 illustrates in plan view a cassette bay of a printing
device 1 according to a second embodiment of the invention. The
cassette receiving bay is shown by the dotted line 26. The cassette
bay 26 includes a thermal print head 16 and a platen 8 which
cooperated to define a print location 3 in a manner which is known
in the art. The print head 16 is pivotable about a pivot point 72
so that it can be brought into contact with the platen 8 for
printing and moved away from the platen 8 to enable a cassette to
be removed and replaced.
[0050] A cassette inserted into the cassette receiving bay 26 is
denoted generally by reference numeral 10. The cassette has a
recess 14 for accomodating the print head 16 and holds a supply
spool 70 of image receiving tape 4 which comprises an image
receiving layer secured to a backing layer by a layer of adhesive.
The image receiving tape 4 is guided by a guide mechanism (which is
not shown) through the cassette 2 through an outlet, past the print
location 3 to a cutting location C. The cassette 2 also has an ink
ribbon supply spool 30 and an ink ribbon take up spool 18. The ink
ribbon 12 is guided from the ink ribbon supply spool 30 through the
print location 3 and taken up on the ink ribbon take up spool 32.
The image receiving tape 4 passes in overlap with the ink ribbon 12
through the print zone 3 with its image receiving layer in contact
with the ink ribbon.
[0051] In the printing device illustrated in FIG. 7, the platen 8
is driven so that it rotates to drive the image receiving tape 4
past the print location P during printing. In this way, tape 4 is
printed and fed out from the print zone 3 to the cutting location
C. The cutting location C is provided at a location on a portion of
the wall of the cassette 2 which is close to the print zone 3. The
portion of the wall of the cassette 2 where the cutting location C
is defined is denoted by reference numeral 74. A slot 76 is defined
in this wall portion 74 and the image receiving tape 4 is fed past
the print zone 3 to the cutting location C where it is supported by
facing wall portions on either side of the slot 76. The printing
device 1 includes a cutting mechanism which is denoted generally by
reference numeral 78. This cutting mechanism 78 includes a cutter
support member 80 which carries a blade 82. The blade 82 has an
angled and sharpened cutting edge. The blade 82 cuts the image
receiving tape 4 and then enters the slot 76 with the leading part
of its egde first, rather than bearing against an anvil. FIG. 7
shows the cutting mechanism 78 in its rady to cut state, that is
with the blade 82 spaced from the tape 4. When the cutter support
member 80 is depressed, the blade 82 is caused to be lowered until
it is in contact with the tape 4. As the cutter support member 80
is further depressed, the blade 82 cuts the tape 4. When the cutter
support member 80 is released, the cutting mechanism is in its
ready-to-cut position under action of springs.
[0052] FIG. 8 illustrates a first embodiment of a cassette for use
in the printing device 1 illustrated in FIG. 7. It comprises a base
40 which is provided with the features necessary for accomodating
the tape 4 and the ink ribbon 12 separately. This cassette 2 is a
refillable base with open reel modules and thus offers the user the
ability to change the ink/substrate combination without buying a
new cassette. For example, ink ribbons of different colours could
be swapped at will, to allow different coloured text to be printed
onto the same reel of image receiving tape. The embodiment
illustrated in FIG. 8 has three main elements: a base 40, an ink
ribbon module comprising an ink ribbon supply bobbin 106 and an ink
ribbon take up bobbin 104, and an image receiving tape module
comprising a tape bobbin 102. The bobbins 102, 104 and 106 are the
cores onto which the tape 4, and the ink ribbon 12 is wound or gets
wound during printing operation. When the ink ribbon is new, the
bobbin 106 and the ink ribbon constitute the supply spool 30, and
when it is used up, the bobbin 104 and the used ink ribbon make up
the ink ribbon take-up spool 32.
[0053] The ink ribbon module is a supply bobbin 106 which is the
core of the ink ribbon supply spool 30, onto which a length of
unused ink ribbon is wound, and a take-up bobbin which is the core
of the ink ribbon take-up spool 32, to which the outer end of the
ink ribbon 12 is attached. The bobbins 104,106 and the ink ribbon
12 may be pre-assembled onto a housing moulding (as in the
embodiment of FIG. 2 or onto a disposable holder (as in the
embodiment of FIG. 10) to assist assembly, but in the illustrated
embodiment of FIG. 8 the user is required to load the bobbins 104,
106 and to thread the ribbon 12 into position by hand. This means,
that the inserted ink ribbon extends from the supply spool 30 on
bobbin 106, which is located on a ink ribbon supply post 84 through
an outlet 107 of the base 40, bridges the recess 14 and thus
extends through the print zone 3, enters the base at an inlet 105
downstream the cutter slot 76, and is then spooled up on ink ribbon
take-up spool 32 on bobbin 104 which is supported on the ink ribbon
take-up support post 86.
[0054] The image receiving tape module consists of a bobbin 102
onto which a length of image receiving tape 4 is wound, the bobbin
102 thus being the core of the image receiving tape supply spool 70
of FIG. 7. As with the ink ribbon, the tape module could include a
plastic housing or holder to assist loading, but is shown here as
an open reel. The bobbin 102 is accomodated on the image receiving
tape support post 88. It should be noted that FIG. 8 shows a
section through the bobbins 102, 104, 106, in order to make their
interior visible. The tape 4 and ink ribbon 12 is removed, as
well.
[0055] The tape and ink ribbon modules can be assembled into or
removed from the base 40 whether the base 40 is in the printer 1 or
not. The refillable base 40 is, in effect, an adaptor for the
printer, allowing it to receive tape module refills.
[0056] Image receiving tapes and ink ribbons of different widths
can be accomodated in the base, and positioned correctly in the
vertical plane, by the use of a datum surface 94 at the base of
each one of the support posts 84,86,88. Bobbins 102,104,106 of
different length (the length corresponding to the tape width) each
feature internal flanges 95 which are designed to sit on the datum
surface 94 and hence provide support for the bobbin, positioned so
that the centre line of the tape 4 or ribbon 12 will alway lie in
the same plane, regardless of its width. The different arrangements
of steps in the bobbin bore shown give the appropriate centering
height for each width of the tape.
[0057] As mentioned above, the support posts 84,86,88 support the
image receiving tape bobbin 102 and ink ribbon bobbins 104,106.
They have clip or "bump" features in the form of an upstanding
horizontal rib 92 which retain the bobbins after the latter are
assembled into the base 40. The clip features are easily deformed
to permit simple removal of used tape and ribbon bobbins. This is
possible since the retention force required to prevent bobbins from
riding up their support posts during printer operation, or to
prevent them from dropping off the posts when installed in
hand-held printers, is minimal. Each bobbin also has an internal
flange at the correct height to mate with the retention rib 92 in
the support post. In this way, different tape widths can be
accomodated on the same base 40.
[0058] The ink ribbon supply bobbin 106 is provided with integral
spring fingers, designed to be deformed when the bobbin 106 is
assembled in the base 40. This is shown in FIGS. 9a and 9b, where
such spring fingers 112 are shown. The bobbin 106 of the ink ribbon
supply spool 30 has integral moulded curved spring fingers 112 in a
plane perpendicular to the axis of the bobbin 106. These spring
fingers 112 are deformed inwards when the bobbin is assembled in a
cylindrical recess in the base 40. The recess could have a
chamfered lead-in to draw the spring fingers 112 radially inwardly
as the bobbin is inserted downwards. The springs cause friction
when the bobbin 102 is turned, giving rise to tension in the ink
ribbon 12 (or image receiving tape 4, when the spring fingers 112
are mounted to the image receiving tape supply spool bobbin 102) as
it is pulled off the spool. The design of the spring fingers 112
(two or more are required) would be appropriate to avoid the danger
of creep over the lifetime of the label printer. This may involve
the selection of the material. Polypropylene for example gives
excellent creep resistance at high strain. Further, the shape has
to be considered: a tapering spring with narrow tips will
effectively spread the strain, rather than concentrating it at the
root of the spring finger for example, and hence prolonging life.
Tension is thus generated in the ink ribbon 12 as it is pulled off
the supply spool 30, because of friction between the spring fingers
112 and the base, which opposes the rotation of the bobbin 106.
[0059] Turning now again to FIG. 8, the base 40 is a single plastic
moulding or subassembly of components containing a selection of
tape guides and support surfaces, support posts for tape and ribbon
bobbins, a cutter interface, and interfaces for the other printer
elements such as a tape size switch, printhead stop, and cassette
retention clips. Whether the base 40 is a single plastic moulding,
or a subassembly of two or more mouldings or other components
depends upon manufacturing simplicity and cost considerations.
[0060] A feature of the base 40 are the guide walls 90. The base 40
contains a number of vertically upstanding walls which are required
to guide and/or restrain the image receiving tape 4 and the ink
ribbon 12, ensuring that they will follow the desired path between
supply spools 70,30, printing location 3, take-up spool 32 (for the
ink ribbon), and (for the image receiving tape) cutter and outlet
positions. The location of the guide walls 90 is similar to those
of known, non refillable tape cassettes.
[0061] Another feature moulded into the base is a tape size switch
interface 98. This interface 98 is designed for interacting with a
switch in the bottom of the cassette receiving portion 26 of the
printing device 1, wherein cassettes housing tapes of different
width require the switch to be moved into different positions,
since the cassette can otherwise not be inserted properly. The
switch is used to provide a controller of the printing device with
an information on the actual tape width. This switch is described
in EP-A-0 634 274. For variants of the cassette 2 which only accept
a single tape width, a boxed recess is moulded into the floor of
the base 40, shaped to fit over the printer's tape size switch with
minimal clearance, and positioned so that the base cannot be
assembled into a printer whose tape size switch is set incorrectly
(ie. to a wrong tape width). Multiple tape width variants would not
have this feature at all, such that the user would have to move the
switch in cassette receiving portion into the appropriate position
(while there is no interaction between the cassette housing and the
switch), or would have it built into a module housing for the image
receiving tape. The image receiving tape refill would therefore be
supplied in a plastic housing containing the image receiving tape
spool 70, location features for fitting it into the base 40, and
the tape size switch interface 98, appropriately positioned.
[0062] Further, there is a pair of vertical walls on the base 40,
which provide two surfaces besides the slot 76 against which the
printer's cutter can act, and between which the cutter blade 82 can
pass into the slot 76. The separation distance between these walls
is critical to the successful operation of the cutter. The walls
which make up the cutter slot 76 and the surfaces supporting the
tape 4 during cutting could be replaceable. This has benefits
because the cutter slot walls can become worn, which leads to
diminished cutter performance. The cutter interface might therefore
be built into the ink ribbon module, so that it would be replaced
whenever the ink ribbon is replaced. The cutter slot walls would be
part of the ink ribbon housing moulding, and would have location
features to ensure that they were correctly aligned with the base.
Walls in the base, behind the cutter area would provide support and
enable the cutter walls to react the force applied by the cutter
clamp. Alternatively, the cutter walls could be available
independently for replacement as and when necessary, regardless of
the tape usage.
[0063] A horizontal surface 100 is provided beneath the tape size
switch interface 98, which is designed to interact with a printhead
stop of the printer. Such a printhead stop is described more
detained in EP-A-0 794 066. It interacts with the printhead holder,
and prevents that the printhead gets in operative contact with the
platen unless a cassette is inserted, in order to avoid deformation
of the platen 8. The stop thus senses the presence of a cassette 2
in the cassette receiving portion 26. The horizontal surface 100
acts on the printhead stop in the printer, lowers it and allows the
printhead to rotate freely into the operative position, ready for
printing. The offset of the horizontal surface 100 from the floor
of the base 40 is critical: too high, and the stop will not be
fully disengaged; too low, and the base 40 will be held off the
floor of the printer's cassette receiving portion 26.
[0064] The printers capable of accomodating the cassette 2 are all
provided with a cassette retention clip mounted behind the
printhead, at a height suitable for the cassettes, and a spring
finger or cushion mounted on the lid of the cassette receiving
portion, which acts on the top surface of an inserted cassette when
the lid is closed. The refillable base 40 therefore features a
horizontal surface 96, above the plane of the top surface of the
tape and ink ribbon spools 30,32,70 against which these mechanisms
can act and hold the cassette 2 in position in the printing device
1.
[0065] Another embodiment of a refillable tape cassette for use in
the printing device of FIG. 7 is illustrated in FIG. 10. This
embodiment is fundamentally a variation on the embodiment of FIG.
8. Whereas in the embodiment of FIG. 8 the cassette 2 has no lid or
overall cover, and the bobbins are retained by clip features on
their support posts, here they are retained by a floating lid 42
which makes contact with their top surfaces. The presence of the
lid 42 has the benefit of preventing dust or other foreign bodies,
which might cause print quality degradation, getting into the
cassette. This embodiment has four main elements: a base 40, an ink
ribbon module, an image receiving tape module, and the lid 42.
[0066] The base 40 is a single plastic moulding or subassembly of
components containing a selection of tape guides and support
surfaces, support posts 84,86,88 for tape and ribbon bobbins
102,104,106, a cutter interface, and interfaces for the tape size
switch and printhead stop. Most of these features are similar to
those of the embodiment shown in FIG. 8. Regarding the interface
between base 40 and lid 42, some differences are to be mentioned:
the external (circumferencial) walls of the base 40 are shorter
than in FIG. 8. The lid 42 is connected to the base 40 by means of
pins 128 of the base which protrude into corresponding holes 130 of
the lid 42. The lid 42 is designed to drop over these pins 128 and
to sit on top of the tape bobbins, when the cassette 2 is
assembled. One central hole 132 in the lid 42 accomodates the tape
supply support post 88. The lid 42 itself is retained by clip arms
48 which protrude upwards from the base. Since the lid 42 can in
certain embodiments be accomodated in different heigths above the
floor of the case 40, the clip 48 is then capable of accomodating
the lid 42 in different heights, or alternatively the lid 42 is
capable of accomodating the clip 48 in different heights. Such a
retention is not necessary on the printhead side because it is
provided by the cassette retention clips and/or springs in the
printer, which have been discussed regarding the embodiment of FIG.
8. In this embodiment the lid 42 (instead of the horizontal surface
96 of the base 40 in FIG. 8) (alternatively it could be the ink
module) provides a surface against which these mechanisms can
act.
[0067] The ink ribbon module comprises a supply spool 30 on an
bobbin 106, onto which a length of unused ribbon is wound, and a
take-up spool 32 with a bobbin 104, to which the outer end of the
ribbon is attached. The bobbins 104,106 and the ink ribbon 12 may
be pre-assembled onto a housing or holder to assist assembly, as in
the illustrated embodiment, where the bobbins 104,106 for the ink
ribbon are mounted to a second lid 120, and fixed to it by means of
a tear-off tape 122. The second lid 120 thus carries the ink ribbon
supply spool 30 and the ink ribbon take-up spool 32, and provides
the necessary guidance for the ink ribbon 12, such that it can be
inserted into the base 40, and the latter can be inserted into the
printing device 1, without any difficulty. When the second lid 120
with the ink ribbon is loaded into the base 40, the tear-off tape
122 is removed and discarded, in order to allow the spools 30,32 to
rotate. It would also be possible to remove and discard the entire
second lid 120 holding the ink ribbon unit. Alternatively, the user
could be required to load the bobbins and thread the ribbon into
position by hand. The ink ribbon supply bobbin can be fitted in
combination with a compression spring which is compressed when the
bobbin is assembled in the base. This is shown in FIG. 11. Tension
is then generated in the ink ribbon as it is pulled off the supply
reel, opposing the rotation of the bobbin, because of friction
between the spring and the base. The level of compression and hence
back tension increases with larger ribbon widths. This has been
shown to be benefical in practice. In FIG. 11a, a bobbin 102 with
relatively wide image receiving tape is shown in a state when it is
mounted onto the tape supply support post 88. In FIG. 11b, a bobbin
102 with medium wide image receiving tape is shown in a state when
it is mounted onto the tape supply support post 88. In FIG. 11c, a
bobbin 102 with relatively narrow image receiving tape is shown in
a state when it is mounted onto the tape supply support post 88. In
each of these Figures a spring 134 between the bobbin 102 and the
mounting surface of the base 40 is comressed between the bottom
flange of the bobbin 102 of the tape supply 70 and the floor of the
base 40 of the cassette. This will create friction and hence
tension when the tape 4 is pulled off the bobbin 102, turning the
latter relative to the cassette 2. The friction produced will
depend on the force applied and will thus be higher for the wide
tape and least for the narrow tape. This is beneficial for the
mechanical performance of the printer 1 since wider tape 4 requires
a higher back-tension. Another arrangement utilising "living"
springs made from the plastic moulding of the mounting part of the
bobbin 102 is shown in FIGS. 12a and b. There, springs 135 extend
downwardly from the tape flange of bobbin 102 adjacent the floor of
the base 40, which are moulded by making plastic material of the
flange extend downwardly. Corresponding arrangements as shown in
FIGS. 11 and 12 can also be used for the ink ribbon supply spool 30
and the ink ribbon take-up spool 32.
[0068] Turning now again to FIG. 10, the image receiving tape
module consists also of a supply bobbin 102 onto which a length of
image receiving tape 4 is wound which constitutes the supply spool
70. As with the ink ribbon, the tape module could include a housing
to assist loading, but is shown here as an open reel. It should be
noted that FIG. 10 shows a section through the bobbins 102, 104,
106, in order to make their interior visible. The tape 4 and ink
ribbon 12 is removed in the drawing for the sake of clarity, as
well. The tape and ink ribbon modules can be assembled into or
removed from the base 40 whether the base is in the printer or
not.
[0069] The lid 42 is a plastic moulding, or could be stamped out in
plastic or card. Its purpose is to help retain the ink and tape
bobbins, and to keep dust or other debris out of the tape paths.
The embodiment of FIG. 10 could use a stamped cardboard lid which
is extremely cheap to produce and which forms part of the retail
packaging of the tape refill unit. A possible embodiment of this
idea is illustrated in FIG. 10. The ink ribbon module is suppled on
a card or plastic holder (former) which holds the ink ribbon in
approximately the right path for loading, and forms part of the
cassette lid 42 after loading. The spools 30,32 are prevented from
turning after loading, by adhesive tape 122 which is peeled off
after the spools 30,32 on the bobbins 106,104 have been dropped
into the cassette base 40. The cardboard holder is removed and
discarded when the ink ribbon 12 has been used up. Similarly, the
substrate tape reel is supplied on a holder which, when loaded into
the printer, forms the remainder of the lid.
[0070] Similar to the embodiment of FIG. 8, tapes 4 and ink ribbons
12 of different widths can be accomodated in the base, and
positioned correctly in the vertical plane, by the use of a datum
surface 94 on each of the support posts 84,86,88. This is performed
like described with respect to the embodiment of FIG. 8, and can be
seen in FIG. 11.
[0071] Reference is now made to FIGS. 13a and 13b, which show an
image receiving tape spool 70 in a side and a top view. In this
arrangement, the image receiving tape 4 comprises a releasable
backing layer 9, which has a width larger than the image receiving
layer as such. This permits the axial ends of the supply spool 70
to be scuffed by a sharp object. This is performed in FIG. 13 at
only one end, but could be done on both ends, as well. Further,
scuffing can be performed across a radius or a diameter, or a
plurality of radii. The image receiving layer is unaffected as the
damage is limited to the edges of the backing tape. This
effectively mechanically links each coil of image receiving tape 14
ot its neighbours and will hinder unwinding, hence making storage
and handling easier. It should be noted that the image receiving
tape could be manufactured without backing paper. The adhesive on
the back of the tape would hold it when coiled until sufficient
force was applied to unwind it, giving it a safe storage
security.
[0072] FIGS. 14a-d show another embodiment of a refillable tape
cassette. The base 40 of the cassette is the same as shown in FIG.
10; however the lid 42 does not float (ie. vary its height over the
floor of the base with the tape width). Instead, the lid 42
contains packing material to bridge the gap between the top of the
tape spools 70 and the top of the base 40 moulding's outer walls.
This means that the top surface of the cassette assembly is always
in the same plane, for all tape sizes. Thus, lid retention is
simplified compared to the embodiment of FIG. 10, because the clip
arm 48 (or arms) only need to accomodate one lid position.
LIST OF REFERENCES
[0073] C cutting location [0074] 1 printing device [0075] 2 upper
cassette (tape cassette) [0076] 3 print zone [0077] 4 image
receiving tape [0078] 5 outlet [0079] 6 recess for platen [0080] 7
lower cassette (ink ribbon cassette) [0081] 8 platen [0082] 9
backing layer [0083] 10 cage moulding [0084] 12 thermal transfer
ribbon [0085] 14 recess for print head [0086] 16 print head [0087]
22 guide portion [0088] 24 guide portion [0089] 26 first cassette
receiving portion [0090] 28 lower cassette receiving portion [0091]
30 ink ribbon supply spool [0092] 32 ink ribbon take-up spool
[0093] 34 guidance [0094] 35 plastic moulded frame [0095] 36
guidance [0096] 37 support post [0097] 40 base [0098] 41 tape
module [0099] 42 lid [0100] 46 hinge [0101] 48 clip [0102] 50
protrusion [0103] 52 recess in base for locating tape module [0104]
54 tapered alignment pin [0105] 56 alignment hole [0106] 58 opening
for accomodating clip [0107] 60 strip of adhesive or wax [0108] 62
stationary magnet [0109] 64 spool magnet [0110] 70 supply spool of
image receiving tape [0111] 72 pivot point [0112] 74 cutting
location [0113] 76 slot [0114] 78 cutting mechanism [0115] 80
cutter support member [0116] 82 blade [0117] 84 ink ribbon supply
post [0118] 86 ink ribbon take up post [0119] 88 tape supply
support post [0120] 90 guide wall [0121] 92 rib [0122] 94 spool
support datum surface [0123] 95 flange [0124] 96 horizontal surface
[0125] 98 tape switch interface [0126] 100 printhead stop interface
[0127] 102 tape bobbin [0128] 104 ink ribbon take up bobbin [0129]
105 inlet [0130] 106 ink ribbon supply bobbin [0131] 107 outlet
[0132] 110 cylindrical recess in base [0133] 112 spring fingers
[0134] 120 floating lid 2 [0135] 122 tear-off tape [0136] 128 lid
alignment pin [0137] 130 lid alignment hole [0138] 132 tape support
post hole [0139] 134 spring [0140] 135 spring [0141] 140 scuff
marking and indent
* * * * *